In remarks he made to a catechetical conference in 2002 Archbishop Chaput addressed it very well:

Second, if we say we're Catholic, we need to act like it. When Catholic Supreme Court Justice Antonin Scalia publicly disputes Church teaching on the death penalty, the message he sends is not so very different from Frances Kissling (of "Catholics for a Free Choice" fame) disputing what the Church teaches about abortion. I don't mean that abortion and the death penalty are equivalent issues. They're not. They clearly do not have equal moral gravity. But the impulse to pick and choose what we accept in Church teaching is exactly the same kind of "cafeteria Catholicism" in both cases.

Of course, this would never satisfy someone who treats Church teaching on the death penalty as a matter of "personal opinion" but regards homosexuality as one of the four great pillars of the Culture of Death. That's not Catholicism; it's a made-up right-wing religion.